The present disclosure relates to various methods for integrating a Group III nitride on a silicon substrate, and various semiconductor structures that are formed using the methods of the present application.
Group III nitride materials are a unique group of semiconductor materials which can be used in a wide variety of applications including, for example, optoelectronics, photovoltaics and lighting. Group III nitrides are composed of nitrogen and at least one element from Group III, i.e., aluminum (Al), gallium (Ga) and indium (In), of the Periodic Table of Elements. Illustrative examples of some common Group III nitrides are GaN, AlN, InN, GaAlN, and GaAlInN. By changing the composition of Al, Ga and/or In within a Group III nitride, the Group III nitride can be tuned along the electromagnetic spectrum; mainly from 210 nm to 1770 nm. This spectrum includes the visible light emitting diode (LED), which is more than a 10 billion dollar industry with a forecasted double digit yearly growth rate. This continuous growth in LED demand enables the infrastructural build-up for the growth and fabrication of Group III nitride based semiconductor devices.
One of the bottlenecks for Group III nitride based semiconductor devices is a lack of a latticed matched substrate. Some of the conventional substrates are sapphire (Al2O3), silicon carbide (SiC), silicon (Si), and zinc oxide (ZnO) that have about 13%, 3%, 17% and 2%, respectively, lattice mismatch with GaN. Currently, lattice matched freestanding GaN and AlN substrates are being developed. However, lattice matched substrates suffer from availability and cost.
Most of the Group III nitride consumer-targeted devices are conventionally grown on sapphire substrates. There is, however, a need for the development of Group III nitride technology on more available and cheaper substrates such as silicon. The integration between Group III nitrides and silicon substrates is difficult because of the different crystal structure and lattice constant of those materials. As such, a method is needed which can be used to easily integrate Group III nitride materials and silicon substrates.